Method for detecting a jammed charge movement flap of an internal combustion engine

Abstract

A method for detecting a jammed charge movement flap of an internal combustion engine, a volumetric air flow of the internal combustion engine being ascertained as a measured volumetric air flow and as a modeled volumetric air flow. In the event of a deviation of the measured volumetric air flow from the modeled volumetric air flow which is greater than a predefined value, a jammed charge movement flap is automatically detected.

1. A method for detecting a jammed charge movement flap of an internal combustion engine, the method comprising:
 ascertaining a measured volumetric air flow of the internal combustion engine and a modeled volumetric air flow of the internal combustion engine; 
 selecting an allowable predefined value from which the measured volumetric air flow may deviate from the modeled volumetric air flow; 
 comparing the measured volumetric air flow and the modeled volumetric air flow to determine if a deviation of the measured volumetric air flow from the modeled volumetric air flow is greater than the predefined value; and 
 in response to a determination that a deviation of the measured volumetric air flow from the modeled volumetric air flow is greater than the predefined value, automatically detecting a jammed charge movement flap. 
 
   
   
     2. The method according to  claim 1 , wherein the deviation of the measured volumetric air flow from the modeled volumetric air flow occurs at an operating point of the internal combustion engine at which the charge movement flap assumes a completely open position as a setpoint position. 
   
   
     3. The method according to  claim 2 , wherein a charge movement flap which is jammed open is detected if the measured volumetric air flow deviates by a first value from the modeled volumetric air flow. 
   
   
     4. The method according to  claim 2 , wherein a charge movement flap which is at least partially jammed closed is detected if the measured volumetric air flow deviates by a second value, which has an absolute value greater than the first value, from the modeled volumetric air flow. 
   
   
     5. The method according to  claim 1 , wherein a position of a throttle valve is incorporated in the modeled volumetric air flow. 
   
   
     6. The method according to  claim 1 , wherein the measured volumetric air flow is determined from a signal of an air flow meter. 
   
   
     7. The method according to  claim 1 , wherein the measured volumetric air flow is determined from a signal of an intake manifold pressure sensor. 
   
   
     8. The method according to  claim 1 , wherein an ambient pressure, which is ascertained using an intake manifold pressure sensor at full load, is incorporated as a reference value in a determination of the modeled volumetric air flow. 
   
   
     9. The method according to  claim 8 , wherein the reference value remains valid only for a limited time. 
   
   
     10. A device, which is a control unit for an internal combustion engine, comprising:
 an ascertaining arrangement for ascertaining a measured volumetric air flow of an internal combustion engine and a modeled volumetric air flow; 
 a selecting arrangement to select an allowable predefined value from which the measured volumetric air flow may deviate from the modeled volumetric air flow; 
 a comparing arrangement to compare the measured volumetric air flow and the modeled volumetric air flow to determine if a deviation of the measured volumetric air flow from the modeled volumetric air flow is greater than the predefined value;and 
 a detecting arrangement to automatically detect a jammed charge movement flap of the internal combustion engine, in response to a determination that a deviation of the measured volumetric air flow from the modeled volumetric air flow is greater than the predefined value.